Early Tirofiban Administration After Intravenous Thrombolysis in Acute Ischemic Stroke

Inclusion Criteria: 1. Age≥18 years old; 2. Clinically diagnosed as acute ischemic stroke and received standard dose (0.25mg/kg) of tenecteplase IVT within 4.5 hours of onset; 3. Total National Institute of Health stroke scale (NIHSS)≥4 or single limb motor item score≥2, and total NIHSS≤15 after IVT; 4. Tirofiban or placebo treatment can be initiated within 6h after IVT; 5. mRS score before onset≤ 1; 6. Intracranial hemorrhage is ruled out by CT head after IVT; Exclusion Criteria: 1. Received or plan to undergo bridge therapy; 2. Large area of infarct indicated by radiological imaging(≥1/3 of middle cerebral artery supply area); 3. Atrial fibrillation or suspected cardiac embolism; 4. Accompanied by epileptic seizures; 5. Using antiplatelet, anticoagulant or fibrinolytic agents within 24h before recruitment; 6. Active bleeding or tendency to bleed after receipt of intravenous thrombolysis; 7. Digestive system bleeding, urinary system bleeding, hemorrhagic retinopathy or other systemic bleeding events within 1 year; 8. Severe renal or liver insufficiency; ALT or AST\>3 times of the upper limit of normal value or above; creatinine clearance rate\<30 mL/min, creatinine\>200μmol/L； 9. Life expectancy less than 3 months; 10. Pregnant or lactating women; 11. Known allergy to tirofiban; 12. Being enrolled or having been enrolled in other clinical trial within 3 months prior to this clinical trial.; 13. Patients who are unwilling to be followed up or likely to have poor treatment compliance; 14. Other situations that the researcher deems unsuitable for inclusion in the study.